Purpose: Professional learning communities (PLCs) have provided a popular means by which schools have used structured collaboration to improve student outcomes. For this reason, the PLC model for collaboration has a strong reputation for helping schools achieve success. However, teachers and administrators regard the PLC efficacy differently. The purpose of this qualitative study was to describe how high school teachers and administrators in Basic Aid funded school districts define success in relation to Professional Learning Community practices. A secondary purpose of this study was to explore the differences in perception between teachers and administrators in regard to defining success in relation to Professional Learning Community practices. Methodology: This study used the qualitative methodology of phenomenology to gather data via semi-structured interviews of eight teachers and eight administrators who work in Basic Aid School Districts in Coastal California that utilize PLC systems. Interview subjects were asked questions influenced by DuFour, DuFour, and Eaker's (2008) PLC framework. Interview responses were recorded, transcribed, and reviewed along with other documents and artifacts to achieve triangulation. Findings: This study arrived at six major findings: 1) teachers perceive that administrators are image oriented, 2) administrators think results are the most important part of PLC work, 3) results are difficult to measure, 4) depression rates are high in high performance schools, 5) there is a need for more teacher leaders, and 6) there is an attitude of complacency in high performance schools. Conclusions: The study's findings led to the following conclusions: 1) teachers are distrustful of administrative motives around issues of student learning, 2) administrators prioritize student test performance over other learning related factors, 3) teachers and administrators are unclear about the link between actions and results, 4) Students in high performance schools face more pressure to succeed, 5) there is a need to grow leadership capacity among teaching staff, and 6) reform in high performance schools lacks a sense of urgency. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]